<%@ page language="java" contentType="text/html; charset=utf-8"
    pageEncoding="utf-8"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
<title>index</title>
</head>
<body>
    <%pageContext.setAttribute("sex", "男"); %>  <!-- 设置值，作用域是当前jsp页面 -->
    <div>
        <%=pageContext.getAttribute("sex") %>   <!-- 注意去看解析后的el_jsp.java，被解析成了out.print(pageContext.getAttribute("sex") ); -->
         Welcome, my friend!
    </div>
    <div>
        ================================================
    </div>
    <div>
         ${sex} Welcome, my friend! <!-- ${expression} EL的语法结构 -->
    </div>
</body>
</html>